Charles e



(No Model.)

0. E. SCRIBNER. H TELEPHONE SWITOHBOARD APPARATUS. No. 544,386.

Patented Aug. 13, 1895.

Evan/fir zarlas Zf'fiara'ina UNITED STATES ATENT OFFICE CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF SAME PLACE.

TELEPHONE-SWITCHB'OARD APPARATUS.

SPECIFICATION forming part of Letters Patent No. 544,386, dated August 13, 1895.

Application filed December 26, 1894. Serial No. 532,960. (No model.)

To all whom it may concern: to complete the connections successively as Be it known that 1, CHARLES E. SCRIBNER, rapidly as possible thereafter. This requirea citizen of the United States, residing at Chiment necessitates the separation of the telecago,1n the county of Cook and State of Illiphone from all but one of the plug-circuits 55 nois, have invented a certain new and useful thus employed and its connection with the Improvement in Telephone-Switchboard Applug-circuits consecutively at a later stage in paratus, (Case No. 372,) of which the following the process of completing the connections. It is a full, clear, concise, and exact description, is to this requirement that my invention is reference being had to the accompanying addressed, its object being, particularly, to 60 IO drawings, forming a part of this specification. bring the operators telephone into connec- My invention relates to the switching aption with a plug-circuit equipped with the paratus of telephone-switchboards, and parbefore-described apparatusinthe act of comticularly to the apparatus controlling the conpleting the connectionthat is, in inserting nection of the attendants telephonic and sigthe final plug of a pair into the spring-jack 65 I5 naling appliances with the telephone-lines. of the answering-line. This I have accom- Its object is to facilitate the work of the opplished by includingin the conductor uniting erator in establishing connection between the telephone with each plugcircuit the lines by automatically controlling the connecswitch-contacts of a plug-seat switch in the tion and disconnection of her telephone with socket of the connecting-plug,the circuit con- 70. the plug-circuit employed in uniting lines. nections being such that the conductor of the As is well known in the art of telephony, telephone is severed while the plug rests'in the essential operations in establishing conits socket. The operator is thus permitted to nections between lines in a switchboard of throw her key into position to connect her ordinary type consists in inserting the an telephone with the plug-circuit at any con- 75 swering-plug of a plug-circuit into the venient time; but the telephone is not actuspring-jaok of a calling subscriber, conneetally connected with the plug-circuit until the ing the operators telephone with the plugoperator has raised the final plug of'a pair circuit to receive'the order, inserting the confrom its socket in the act of completing a renecting-plug in a spring-jack of the subquired connection. 3O scribercalled for,disconnectingthe telephone, My invention is particularly applicable to and signaling over the line called for. the multiple type of switchboards, in which it Hitherto the disconnection of the telephone is desirable that the telephone shall remain and the transmission of the calling-signal connected with the plug-circuit until the over the line called for have been effected test. has been made. 5

simultaneously by a single key, which in its I have illustrated my invention in the acnormal position connected the operators telecompanying drawings, and will describe it phone with the plug-circuit. The key is more fully in connection therewith. placed in its normal position by the operator Figurel in the drawings represents two subat her leisure, so that upon the insertion of stations A and B, connected by liue-conduc- 90 th answering-plug in the spring-jack of a tors with the usual apparatus of a multiple calling-line, the telephone is found already telephone-switchboard of two sections. Fig. connected with the plug-circuit. The move- 2 is a side elevation of a key particularly suitments of an operator in making connection able for use in my invention. Fig. 3 is a View between two lines are thus limited to the inof the same from beneath, showing the ar- 95 sertion of the two plugs and the operation of rangement of the switch-springs.

the key for signaling the subscriber called In Fig. 1 the apparatus at the sub-station. for. It has been found in practice, however, may comprise a telephone aand microphone that it is convenient for an operator receiva, a signal-bell a a generator at of signaling several calls simultaneously to insert the ing-current, and an automatic telephone- 0 answering-plugs of a number of plug-circuits switch 0; arranged to switch the telephonic into the spring-jacks of the calling-lines and and the signaling appliances alternately in connection with the line. The apparatus at station A is connected by line-wires 1 and 2 with spring-jacks c and 0, one upon each section at and d of the multiple switchboard. The line is also connected with an annunciator e of the self-restoring type. Each springjack consists of a pair of springs and f, which constitute the terminal contacts of the line-circuit 1 2, and a pair of contact-pieces f f which constitute the normally open or separated terminals of a local battery-circuit for restoring the annunciator and providing the busy test. The contact-pieces f of the jacks belonging to one line are connected together by a conductor 3 and to earth through a battery g. The remaining contact-pieces f are connected with a conductor 4-, which includes the resetting or restoring magnet 71 of the line-annunciator 0; but one pair 2' z" of connecting-plugs, with their accessory circuits and mechanism, is shown in the drawings. Each plug is constructed with a spherical tip 7c and a short sleeve which are adapted to register with the line-contacts ff of a springjaek in which the plug is inserted, and a longer sleeve 70*, which makes connection between the contact-rings f f of the springjack. The tips k of the plugs t' and t" are united by a flexible cond uetor 5 and the sleeves is by a conductor 6.

The switch-springs of a combined listening. and calling key Z are connected with the conductors 5 and 6 in a manner which will be traced after the description of the key, the function of the key being to control the connection with the plug-circuit 5 6 of the operators telephone m and a source a of signaling-current.

Referring to Figs. 2 and 3, the keyZ is seen to consist of a pivoted lever Z, which is adapted to assume three positions, carrying at its lower extremity a wedge or plunger Z and two sets of switch-springs Z l and Z Z, respectively, between which the plunger may be thrust alternately to change their circuit connections. \Vhen the lever Z is thrust into one oblique position the wedge or block Penters between the curved ends of springs Z Z and forces them outward. When throwninto the opposite oblique position, it enters between springs Z Z and presses these 'apart. The springs Z Z are provided with anvils Z 1 against which they are thrust when forced outward. Springs Z Z have each two sets of anvils Z Z and Z 1", from the former of which they are separated, respectively, when the plunger enters between them, and against the latter of which they are thrust. Stops limit the movement of the lever, the stops being so disposed that the wedge Z is permitted to enter so far between springs Z and Z that it is held between them until forcibly returned to its central position, but that when it is thrust between springs Z 1 it is pressed out from between them when released.

Returning to Fig. 1, the spring Z and the anvil Z are connected with the conductor5 of the plug-circuit and the-spring Z and anvil Z with conductor 6. The other switch-springs Z l are connected with the line-contacts 7c 70' of plug 1''. Anvils Z Z constitute the terminals of the operators telephone set 122, while the other pair of anvils Z Z are connected with the poles of the generator H of signalingcurrent.

The continuity of the circuit containing the telephone set m is controlled by a plugseat switch 0 in the socket of connecting-plug 1.. This plug-seat switch comprises only a spring 0, which projects into the socket of the plug and is adapted to be forced aside while the plug rests in its seat, and an anvil 0' against which the spring is pressed when it is permitted to project into the socket. These contact-points are in circuit in the conductor 7, which includes the telephone. The operators telephone-receiver is grounded at the middle of its coil for testing purposes, as usual. A clearing-out annunciator p is permanently connected in a bridge between conductors 5 and 6.

In the normal position of the apparatus the plug 2" rests in its socket as shown, and the lever Z of keyl is thrown into position to connect the telephone with springs Z Z It will be noted that the telephone-circuit is open, however, at the plug-seat switch 0.

In order to trace the operation of this system, let it be assumed that subscriber at station A wishes to converse with subscriber at station B. The-former subscriber by operating his signaling-generator 0. transmits a current in line 1 2, which causes annunciator e to display its indicator. The operator at switchboard d, observing this signal, inserts plug 2' into spring-jack c of the corresponding line. The signal of annunciator 6 may be one of a number of signals occurring simultaneously. The operator therefore inserts the answeringplugs t' of a number of diiferent pairs of plugs into spring-jacks ot' the different calling-lines; but her telephone is not as yet connected with any plug-circuit. At her convenience, however, she raises plug 2' from its seat, preparatory to inserting it into the spring-jack of a line which may be called for. By this act the conductor 7 is completed and the telephone at is brought into connection with plug-circuit 5 6, and the operator is permitted to receive the order of subscriber at station A for the connection desired. She then tests the line called for, to determine that it is free, in the usual waythat is, by applying the tip 70 of plug t" to the test ring or thimble f of spring-jack 0 It will be understood that it this line were in use the battery 9 would be connected through the sleeve 70 of the plug already inserted in the spring-jack of the line with conductor 4:, and hence with the test ringf, and at each application of test-plug 2" to the test-ring current would find circuit from test-ringf through conductor 5 to the spring Z thence to its anvil Z through contacts 0' 0 of the plug-seat switch and through one-half of the telephone-receiver m to earth, producing a click in the telephone. Having found the line free, however, the operator inserts plug 2" fully into spring-jack c and places lever Z in position for ringingthat is, in that position in which the wedge Z is forced between springs Z Z These springs are thus separated from their normal resting-anvils Z Z and are closed upon the contacts 1 Z whereby the generatornis looped into circuit with the line-contacts of the plug, and a signaling-current is transmitted to station E which operates the signal-bell there. When the lever Z is left free, after the operation of ringing, it returns to its normal vertical position. The conductors 5 6 are thus completed between plugs 1 2, so that the line-circuits 1 2 and 8 9 are connected together in a complete metallic circuit, but the springs Z 1 are permitted to separate from theiranvils and thus to disconnect both terminals of the telephone from the plug-circuit.

When the subscribers have terminated their conversation, one of them may, by rotating his signaling-generator, operate the clearingout annunciator p, the signaling-current finding circuit to conductors 5 and 6 and thence through the clearing-out annunciator. When the operator has noted this signal, it is customary for her to bring her telephone again into connection with the circuit to assure herself that the connection is no longer desired. Having found that the connected subscribers are no longer in conversation, she removes the plugstt" from the spring-jacks and returns them to their idle positions, leaving the keyZ in its position of connecting the telephone with the plug-circuit. This circuit is, of course, now open, however, at the switchcontacts of plug-seat switch 0.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination with a telephone line, of a springjack connected therewith, a plug forming one terminal of aplug circuit inserted in the springjack, an operators telephone in a conductor connected with the plug circuit, a plugforming the other terminal of the plug circuit, and a plug-seat-switch in the resting socket of the latter plug, the separated switch contacts of the plug-seat-switch being included in the conductor containing the telephone, whereby the telephone may be brought into complete connection with the plug circuit by removing the plug from its socket to complete a connection.

2. The combination with a telephone line, of a connecting plug forming the terminal of the line, a switch key adapted to connect an operators telephone with the line, a plug-seatswitch in' the resting socket of the plug having normally separated switch contacts included in circuit with the telephone,a calling key adapted to connect a source of signaling current with the terminal plug, and mechanism adapted to be actuated in the operation of the calling key to return the listening key to its position of disconnecting the telephone, substantially as described.

3. The combination with a telephone circuit, of a plug constituting the terminal thereof, a switch key capable of being thrown into three different positions, in one of which it connects an operators telephone with the telephone line, in another of which it disconnects the said telephone, and in the third of which it connects a source of signaling current with the terminal plug, and a plug-seatswitch having normally separated contacts included in circuit with the telephone, whereby raising the plug to make connection closes the circuit through the telephone, and operating the calling keys opens the circuit through the telephone.

4:. In combination, several pairs of connecting plugs with their uniting plug circuits, a telephone and listening key for each plug circuit adapted to connect the terminals of a conductor including the telephone with the corresponding plug circuit, a plug-seat-switch for the final or test plug of each pair, the switch contacts thereof being included in the conductor between the telephone and the corresponding plug circuit to open the connection normally, a calling key and mechanism for simultaneously operating the calling key to signal and the listening key to disconnect the telephone, substantially as described.

In witness whereof I hereunto subscribe my name this 30th day of November, A. D. 1894:.

CHARLES E. SCRIBNER. Witnesses:

ELLA EDLER, DUNCAN E. WILLETT.

ICO 

